Merge branch 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 vdso changes from Peter Anvin:
 "This is the revamp of the 32-bit vdso and the associated cleanups.

  This adds timekeeping support to the 32-bit vdso that we already have
  in the 64-bit vdso.  Although 32-bit x86 is legacy, it is likely to
  remain in the embedded space for a very long time to come.

  This removes the traditional COMPAT_VDSO support; the configuration
  variable is reused for simply removing the 32-bit vdso, which will
  produce correct results but obviously suffer a performance penalty.
  Only one beta version of glibc was affected, but that version was
  unfortunately included in one OpenSUSE release.

  This is not the end of the vdso cleanups.  Stefani and Andy have
  agreed to continue work for the next kernel cycle; in fact Andy has
  already produced another set of cleanups that came too late for this
  cycle.

  An incidental, but arguably important, change is that this ensures
  that unused space in the VVAR page is properly zeroed.  It wasn't
  before, and would contain whatever garbage was left in memory by BIOS
  or the bootloader.  Since the VVAR page is accessible to user space
  this had the potential of information leaks"

* 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  x86, vdso: Fix the symbol versions on the 32-bit vDSO
  x86, vdso, build: Don't rebuild 32-bit vdsos on every make
  x86, vdso: Actually discard the .discard sections
  x86, vdso: Fix size of get_unmapped_area()
  x86, vdso: Finish removing VDSO32_PRELINK
  x86, vdso: Move more vdso definitions into vdso.h
  x86: Load the 32-bit vdso in place, just like the 64-bit vdsos
  x86, vdso32: handle 32 bit vDSO larger one page
  x86, vdso32: Disable stack protector, adjust optimizations
  x86, vdso: Zero-pad the VVAR page
  x86, vdso: Add 32 bit VDSO time support for 64 bit kernel
  x86, vdso: Add 32 bit VDSO time support for 32 bit kernel
  x86, vdso: Patch alternatives in the 32-bit VDSO
  x86, vdso: Introduce VVAR marco for vdso32
  x86, vdso: Cleanup __vdso_gettimeofday()
  x86, vdso: Replace VVAR(vsyscall_gtod_data) by gtod macro
  x86, vdso: __vdso_clock_gettime() cleanup
  x86, vdso: Revamp vclock_gettime.c
  mm: Add new func _install_special_mapping() to mmap.c
  x86, vdso: Make vsyscall_gtod_data handling x86 generic
  ...

1 files changed, 16 insertions, 6 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 121d5fcbd94a..2311dad7a57a 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -3424,14 +3424,24 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 					of CONFIG_HIGHPTE.
 
 	vdso=		[X86,SH]
-			vdso=2: enable compat VDSO (default with COMPAT_VDSO)
-			vdso=1: enable VDSO (default)
+			On X86_32, this is an alias for vdso32=.  Otherwise:
+
+			vdso=1: enable VDSO (the default)
 			vdso=0: disable VDSO mapping
 
-	vdso32=		[X86]
-			vdso32=2: enable compat VDSO (default with COMPAT_VDSO)
-			vdso32=1: enable 32-bit VDSO (default)
-			vdso32=0: disable 32-bit VDSO mapping
+	vdso32=		[X86] Control the 32-bit vDSO
+			vdso32=1: enable 32-bit VDSO
+			vdso32=0 or vdso32=2: disable 32-bit VDSO
+
+			See the help text for CONFIG_COMPAT_VDSO for more
+			details.  If CONFIG_COMPAT_VDSO is set, the default is
+			vdso32=0; otherwise, the default is vdso32=1.
+
+			For compatibility with older kernels, vdso32=2 is an
+			alias for vdso32=0.
+
+			Try vdso32=0 if you encounter an error that says:
+			dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
 
 	vector=		[IA-64,SMP]
 			vector=percpu: enable percpu vector domain